I've taken many "breaks" from being on Adderall XR. The good news is that it should go away within a week, maximum, and usually about 3 days (for me). The bad news is everytime I stop it, I basically sleep for a few days straight, only waking up when absolutely necessary or to eat and go back to bed. I feel really detatched from reality and frequently forget where I am going when driving. However, this is stuff I did before the medication...I just think it's somehow worse (or maybe just seems that way) after abruptly stopping it.
It'll go away. They say it's good to take "mini-breaks" from amphetamines because of the addiction/detox factor, but my shrink recommended no more than a week generally. Usually I'll just take 1 or 2 days off on a weekend every other month or so.